The continuation of the kinetic investigation of the mechanism of DNA conformation changes is proposed. Rate measurements would be undertaken in a stopped-flow instrument by changing the pH of the nucleic acid solutions and monitoring the ensuing rapid conformation change spectrophotometrically at 260 nm. The investigations completed so far have revealed the mechanism of the reversible double-helix/random-coil conformation change of poly(d(A-T)), a synthetic DNA analog. The proposed work would continue with the study of the unfolding/refolding mechanism of two relatively simple native DNAs, crab d(AT) and human satellite DNA. These investigations, in turn, would be followed by kinetic measurements on more complex deoxyribonucleic acids.